Thrust rings are commonly used to carry thrust loads between rotating parts in a wide variety of types of machinery. Many different types of lubrication strategies for thrust rings and associated components are also well known and have been used in connection with thrust rings for well over a century. Grease, lubricating oils, and even solid materials such as graphite and adherent polypropylene stickers are used to lubricate surfaces of thrust rings and the metallic components with which they may come in contact. Insufficient lubrication can cause all manner of problems, among them galling, fretting and even cracking of certain components. These and other wear-related processes can, over time, deform components or remove sufficient material that specified tolerances of and among the machinery components are compromised. While some “break-in” is expected and even desirable in most thrust ring systems, where wear exceeds some threshold, operation of the associated system can be compromised or fail altogether. Changes in component tolerance and geometry can also negatively impact the capability of a thrust ring system to continue to be lubricated as intended. In other words, since a given lubrication strategy may rely upon specified dimensions, tolerances and even surface characteristics of rotating parts, excessive wear or other material changes can compromise an overall lubrication strategy and hasten failure of the system.
Ground engaging track used in tracked machines is one environment where thrust rings have been used to react axial loads for many years. In a conventional system, thrust rings are placed between adjacent track links to react axial loads, or loads having an axial component, through the track. Construction, mining, earth moving, and a variety of other activities can require profoundly robust thrust rings and other track components. Preservation of sufficient lubrication between and among the track components for an entirety of a track service life, or field duty cycle between planned service intervals, can also be critical. The negative impact of downtime due to unscheduled maintenance or repair for many tracked machines needs no further explanation.
One known thrust ring for machine track commonly used in track-type tractors includes an annular body having relatively small grooves on each axial side of the annular body. This known design includes two grooves on each axial side positioned at 180° from one another. The grooves on each axial side are positioned at the same circumferential location about a center axis of the thrust ring as are the grooves on the opposite axial side. The purpose of the grooves is to provide a path for oil contained within an oil reservoir of the track to pass between an inside of the thrust ring and an outside of the thrust ring, and also flow onto the thrust surfaces which are on each axial side of the thrust ring and contact adjacent components of the track such as a track link or cartridge pin collar. Thrust rings of this general type have been used for many years. It has been discovered that lubricant may fail to enter the interfaces between the thrust ring and abutting components leading to accelerated wear and premature failure. It is believed that the invention disclosed herein overcomes this problem by facilitating the entry of lubricant into these interfaces while balancing the need for structural strength in the load ring.